Changing Start Dates adjusts Resource Usage

[Jane Sherman]

I am using MS Project as a Resource Planning tool. I
enter a task and then use the Resource Usage sheet to
enter specific time per week for the person on the task.
If I adjust the Start Date on the Task Sheet, it "re-
levels" the time on the Resource Usage sheet. I'd really
like it to shift the time down, not re-level.

For example,

I enter a task, Task 1, duration of two weeks, Work for 3
days (I know the person is going to spend 3 days over the
next 2 weeks on the task) and it's assigned to Resource 1.

Go into the usage sheet and actually enter 3 days during
those 2 weeks.

Then go back to the task sheet and change the start
date. Go back to the usage sheet. It's leveled all of
that time again and I have to re-enter the 3 specific days.

 

[Steve House]

Duration is measured from the moment when work begins until the moment it's
complete and by default proceeds at a constant rate between the two. The
duration of a task IS NOT the "window of opportunity" during which work
*could* take place, it is the time period over which you expect it *will*
take place. If you change the start date of a task, you are telling Project
that the actual work will start on a different date than was posted
previously. So if I have a task that is showing 2 weeks duration starting
next Monday and enter that the resource is doing 3 days of work, I'm telling
Project that the resource is work 3/10 of a day on each day of the task
starting on Monday and continuing at that rate every day for 2 weeks. If I
now go in and say the resource is doing 1 day each next Wed, Thur, and Fri,
it's no longer a 2 week task starting Mon with him assigned at 33%, it's a 3
day task assigned at 100% starting Wed. If I say he is doing 1 day each on
Wed, Fri, and following Tue, it is now a 5 day task averaging 66% also
starting Wed.

Are you changing the start date to make it earlier or later? What is your
task type - fixed work, duration, or effort? What do you mean by your use
of the term "re-levels" as evenly distributing the work over the duration is
NOT what the term "resource leveling" means. And finally, what do you mean
you want it to do when you say you want it to "shift the time down?" Can
you give a concrete example of the results you think you should get?

FYI, you really should never, ever, be specifying the start date of the
tasks in the task list, with the exception of tasks that have constraints
imposed on them by external factors. Entering dates always establishes a
Start No Earlier Than constraint on the task which is rarely justified. The
basis for Project is to calculate the schedule for you, not passively
illustrate a schedule you have derived elsewhere. In the best of all
worlds, you specify just one date, the project start date, and from that
Project calculates a schedule of all the task start and finish dates for
you, derived from task durations, predecessor links, and resource
availability. It's the calculator you use when designing the schedule at
the get-go.

Steve House [MVP]
MS Project Trainer/Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs